Look at the code below. There's two DelegateCommand that are set in Views's constructor:
public DelegateCommand DeletePromotionCommand { get; set; }
public DelegateCommand EditPromotionCommand { get; set; }
public PromotionDetailViewModel(INavigationService navigationService, IPageDialogService pageDialogService)
: base(navigationService, pageDialogService)
{
Title = "Promoção";
DeletePromotionCommand = new DelegateCommand(DeletePromotion, CanDeletePromotion);
EditPromotionCommand = new DelegateCommand(EditPromotion, CanEditPromotion);
}
The CanEditPromotion is called when the EditPromotionCommand is set in the constructor. CanEditPromotion method is shown below:
private bool CanEditPromotion()
{
var userString = Preferences.Get("user", string.Empty);
if (userString == string.Empty)
return false;
var userId = (Guid)JObject.Parse(userString)["id"];
if (userId == Promotion.CreatedBy)
return true;
else
return false;
}
Note that on the 4th sentence I need the Promotion property. This property need to be set before the Views's constructor, so it will be null and, at exactly line, it will break the app.
Before I should use the code below to set Promotion property, but Prism doesn't have OnNavigatingTo method anymore. Promotion info comes from the Page before and is passed as a parameter navigation:
public override async void OnNavigatingTo(INavigationParameters parameters)
{
base.OnNavigatedTo(parameters);
try
{
IsBusy = true;
Promotion = parameters["promotion"] as Promotion;
var marketService = new Service<Market>();
Market = await marketService.GetAsync(Promotion.MarketId);
IsBusy = false;
}
catch (Exception)
{
IsBusy = false;
}
}
When I try to use INavigatingTo at my BaseViewModel, it is show to me a message saying to use IInitialize instead. I tried but the Initialize method is still fired after the View's constructor.
As is indicated in the official release notes for Prism 7.2 OnNavigatingTo was deprecated due after a lot of consideration and feedback from the Prism community. This was in part due to the fact that OnNavigatingTo was expected to run to Initialize your ViewModel prior to the View being pushed onto the Navigation Stack. The issue is that over time its intent was getting lost and people were trying to misuse the API. The only way for us to move forward was to remove the reference to INavigatingAware from INavigationAware which unfortunately creates a soft break in which OnNavigatingTo simply isn't called. In the case where you have a direct reference to INavigatingAware you will get a hard compilation error.
To migrate your code you should use the new initialization API with either IInitialize, IInitializeAsync or IAutoInitialize. Assuming that you simply use IInitialize you'll update your legacy code from:
public void OnNavigatingTo(INavigationParameters parameters)
{
// your code here
}
to the new IInitialize version
public void Initialize(INavigationParameters parameters)
{
// your code here
}
Keep in mind that if you use the Async version of this the long running task will have to complete before the page is pushed thus causing a noticeable delay in navigation. It may often be more desirable therefore to simply use async void to avoid blocking the Navigation.
You can read more in the Prism 7.2 Release Notes here
I resolved this way:
At CanEditPromotion I put a null verification for Promotion property:
private bool CanEditPromotion()
{
var userString = Preferences.Get("user", string.Empty);
if (userString == string.Empty)
return false;
var userId = (Guid)JObject.Parse(userString)["id"];
if (Promotion != null && userId == Promotion.CreatedBy)
return true;
else
return false;
}
And I observe the Promotion property when the EditPromotionCommand is set:
public DelegateCommand DeletePromotionCommand { get; set; }
public DelegateCommand EditPromotionCommand { get; set; }
public PromotionDetailViewModel(INavigationService navigationService, IPageDialogService pageDialogService)
: base(navigationService, pageDialogService)
{
Title = "Promoção";
DeletePromotionCommand = new DelegateCommand(DeletePromotion, CanDeletePromotion)
.ObservesProperty(() => Promotion);
EditPromotionCommand = new DelegateCommand(EditPromotion, CanEditPromotion)
.ObservesProperty(() => Promotion);
}
And I used the OnNavigatedTo method to set Promotion property:
public override async void OnNavigatedTo(INavigationParameters parameters)
{
try
{
IsBusy = true;
Promotion = parameters["promotion"] as Promotion;
var marketService = new Service<Market>();
Market = await marketService.GetAsync(Promotion.MarketId);
IsBusy = false;
}
catch (Exception)
{
IsBusy = false;
}
}
The Custom Pipeline component developed reads the incoming stream to a folder and pass only some meta data through the MessageBox.I am using the one already availaible in Code Project
using System;
using System.Collections.Generic;
using System.Text;
using Microsoft.BizTalk.Message.Interop;
using Microsoft.BizTalk.Component.Interop;
using System.IO;
namespace SendLargeFilesDecoder
{
[ComponentCategory(CategoryTypes.CATID_PipelineComponent)]
[ComponentCategory(CategoryTypes.CATID_Decoder)]
[System.Runtime.InteropServices.Guid("53fd04d5-8337-42c2-99eb-32ac96d1105a")]
public class SendLargeFileDecoder : IBaseComponent,
IComponentUI,
IComponent,
IPersistPropertyBag
{
#region IBaseComponent
private const string _description = "Pipeline component used to save large files to disk";
private const string _name = "SendLargeFileDecoded";
private const string _version = "1.0.0.0";
public string Description
{
get { return _description; }
}
public string Name
{
get { return _name; }
}
public string Version
{
get { return _version; }
}
#endregion
#region IComponentUI
private IntPtr _icon = new IntPtr();
public IntPtr Icon
{
get { return _icon; }
}
public System.Collections.IEnumerator Validate(object projectSystem)
{
return null;
}
#endregion
#region IComponent
public IBaseMessage Execute(IPipelineContext pContext, IBaseMessage pInMsg)
{
if (_largeFileLocation == null || _largeFileLocation.Length == 0)
_largeFileLocation = Path.GetTempPath();
if (_thresholdSize == null || _thresholdSize == 0)
_thresholdSize = 4096;
if (pInMsg.BodyPart.GetOriginalDataStream().Length > _thresholdSize)
{
Stream originalStream = pInMsg.BodyPart.GetOriginalDataStream();
string srcFileName = pInMsg.Context.Read("ReceivedFileName", "http://schemas.microsoft.com/BizTalk/2003/file-properties").ToString();
string largeFilePath = _largeFileLocation + System.IO.Path.GetFileName(srcFileName);
FileStream fs = new FileStream(largeFilePath, FileMode.Create);
// Write message to disk
byte[] buffer = new byte[1];
int bytesRead = originalStream.Read(buffer, 0, buffer.Length);
while (bytesRead != 0)
{
fs.Flush();
fs.Write(buffer, 0, buffer.Length);
bytesRead = originalStream.Read(buffer, 0, buffer.Length);
}
fs.Flush();
fs.Close();
// Create a small xml file
string xmlInfo = "<MsgInfo xmlns='http://SendLargeFiles'><LargeFilePath>" + largeFilePath + "</LargeFilePath></MsgInfo>";
byte[] byteArray = System.Text.Encoding.UTF8.GetBytes(xmlInfo);
MemoryStream ms = new MemoryStream(byteArray);
pInMsg.BodyPart.Data = ms;
}
return pInMsg;
}
#endregion
#region IPersistPropertyBag
private string _largeFileLocation;
private int _thresholdSize;
public string LargeFileLocation
{
get { return _largeFileLocation; }
set { _largeFileLocation = value; }
}
public int ThresholdSize
{
get { return _thresholdSize; }
set { _thresholdSize = value; }
}
public void GetClassID(out Guid classID)
{
classID = new Guid("CA47347C-010C-4B21-BFCB-22F153FA141F");
}
public void InitNew()
{
}
public void Load(IPropertyBag propertyBag, int errorLog)
{
object val1 = null;
object val2 = null;
try
{
propertyBag.Read("LargeFileLocation", out val1, 0);
propertyBag.Read("ThresholdSize", out val2, 0);
}
catch (ArgumentException)
{
}
catch (Exception ex)
{
throw new ApplicationException("Error reading PropertyBag: " + ex.Message);
}
if (val1 != null)
_largeFileLocation = (string)val1;
if (val2 != null)
_thresholdSize = (int)val2;
}
public void Save(IPropertyBag propertyBag, bool clearDirty, bool saveAllProperties)
{
object val1 = (object)_largeFileLocation;
propertyBag.Write("LargeFileLocation", ref val1);
object val2 = (object)_thresholdSize;
propertyBag.Write("ThresholdSize", ref val2);
}
#endregion
}
}
The issue here is the LargeFileLocation is configurable in the receive pipeline. If I give a location for the first time for example E:\ABC\ the files are sent to the location.
But if I change the location to E:\DEF\ the files are still being sent to the previous location E:\ABC. I tried to create a new biztalk application deleting the old one but still I get the files dropped in to the old location E:\ABC\ not sure why.
Most likely the issue is with respect to Property definition of LargeFileLocation and its implementation and usage in IPersistPropertyBag interfaces. You can try following things:
Check if you have added E:\ABC path in Pipeline at design time. If
yes remove it from there and set in Admin console for first time
also and see how it behaves, my feeling is it will take temp path
location.
Change the Properties and IPersistPropertyBag implementation to use property with declaration such as public string LargeFileName {get;set;} i.e. no local variables _largeFileName.
Have you deleted the dll in %BizTalkFolder%\Pipeline Components\ ?
To refresh the pipeline component, you need delete the old dll file/remove the item in VS toolbox. then restart the VS, deploy it again.
and for this LargeFileLocation , I suggest you make it as a property so you can config it.
I have a Windows 8 store app based off of the grouped template project, with some renames etc. However, I'm having a hard time getting the ItemsSource databinding to work for both non-snapped and snapped visual states.
I have a property, that, when set, changes the ItemsSource property, but I can only get one of the controls to bind at a time (either the GridView for non-snapped, or the ListView for snapped).
When I use the following, only the non-snapped binding works and the snapped binding shows no items:
protected PickLeafModel ListViewModel
{
get
{
return (PickLeafModel)m_itemGridView.ItemsSource;
}
set
{
m_itemGridView.ItemsSource = value;
m_snappedListView.ItemsSource = value;
}
}
If I comment out one of the setters, the snapped view shows items but the non-snapped view shows nothing:
protected PickLeafModel ListViewModel
{
get
{
return (PickLeafModel)m_itemGridView.ItemsSource;
}
set
{
//m_itemGridView.ItemsSource = value;
m_snappedListView.ItemsSource = value;
}
}
It's as if I can bind my view model only to one property at a time. What am I doing wrong?
Since I am generating my data model on another thread (yes, using the thread pool), I cannot make it inherit from DependencyObject. If I do, I get a WrongThreadException.
So to make it work I have done the following:
public class PickLeafModel : IEnumerable
{
public PickLeafModel()
{
}
public IEnumerator GetEnumerator()
{
if (m_enumerator == null)
{
m_enumerator = new PickLeafModelViewDataEnumerator(m_data, m_parentLeaf);
}
return m_enumerator;
}
private SerializableLinkedList<PickLeaf> m_data =
new SerializableLinkedList<PickLeaf>();
}
and then my items look like this:
// Augments pick leafs by returning them wrapped with PickLeafViewData.
class PickLeafModelViewDataEnumerator : IEnumerator
{
public PickLeafModelViewDataEnumerator(
SerializableLinkedList<PickLeaf> data, PickLeaf parentLeaf)
{
m_viewDataList =
new System.Collections.Generic.LinkedList<PickLeafViewData>();
foreach (PickLeaf leaf in data)
{
PickLeafViewData viewData = new PickLeafViewData();
viewData.copyFromPickLeaf(leaf, parentLeaf);
m_viewDataList.AddLast(viewData);
}
m_enumerator = m_viewDataList.GetEnumerator();
}
public void Dispose()
{
m_viewDataList = null;
m_enumerator = null;
}
public object Current
{
get
{
return m_enumerator.Current;
}
}
public bool MoveNext()
{
return m_enumerator.MoveNext();
}
public void Reset()
{
m_enumerator.Reset();
}
private IEnumerator<PickLeafViewData> m_enumerator = null;
private System.Collections.Generic.LinkedList<PickLeafViewData>
m_viewDataList;
}
}
Is there something I'm doing fundamentally wrong?
Help appreciated.
Thanks!
Thankfully there is a much easier way to do what you are trying!
Create a class called your ViewModel as shown below:
public class DataViewModel
{
public DataViewModel()
{
Data = new ObservableCollection<PickLeafViewData>(new PickLeafModelViewDataEnumerator(m_data, m_parentLeaf));
}
public ObservableCollection<PickLeafViewData> Data
{
get;
set;
}
}
Now on the code behind set the Page.DataConected to equal an instance of the above class.
And finally on both your snapped listview, and the grid view set the item source to this:-
ItemsSource="{Binding Data}"
That should work nicely for you.
Thanks to Ross for pointing me in the right direction.
I'm not 100% happy with this solution, but it does work. Basically the idea is that after I get back the PickLeafModel from the worker threads, I transplant its internal data into a derived version of the class which is data binding aware.
public class PickLeafViewModel : PickLeafModel, IEnumerable
{
public PickLeafViewModel()
{
}
public PickLeafViewModel(PickLeafModel model)
{
SetData(model);
}
public void SetData(PickLeafModel model)
{
model.swap(this);
}
public IEnumerator GetEnumerator()
{
if (m_observableData == null)
{
m_observableData = new ObservableCollection<PickLeafViewData>();
var data = getData();
PickLeaf parentLeaf = getParentLeaf();
foreach (PickLeaf leaf in data)
{
PickLeafViewData viewData = new PickLeafViewData();
viewData.copyFromPickLeaf(leaf, parentLeaf);
m_observableData.Add(viewData);
}
}
return m_observableData.GetEnumerator();
}
and the page code is as follows:
protected PickLeafViewModel ListViewModel
{
get
{
return DataContext as PickLeafViewModel;
}
set
{
DataContext = value;
}
}
whenever I want to set ListViewModel, I can do this:
ListViewModel = new PickLeafViewModel(model);
and swap looks like:
private static void swap<T>(ref T lhs, ref T rhs)
{
T temp;
temp = lhs;
lhs = rhs;
rhs = temp;
}
// Swaps internals with the other model.
public void swap(PickLeafModel other)
{
swap(ref m_data, ref other.m_data);
...
Also, PickLeafModelViewDataEnumerator can be deleted altogether.
"How can i use engine in my console application"
I shouldn't use the ITemplate-interface and Transform-Method.
I am using Tridion 2011
Could anyone please suggest me.
You can't. The Engine class is part of the TOM.NET and that API is explicitly reserved for use in:
Template Building Blocks
Event Handlers
For all other cases (such as console applications) you should use the Core Service.
There are many good questions (and articles on other web sites) already:
https://stackoverflow.com/search?q=%5Btridion%5D+core+service
http://www.google.com/#q=tridion+core+service
If you get stuck along the way, show us the relevant code+configuration you have and what error message your get (or at what step you are stuck) and we'll try to help from there.
From a console application you should use the Core Service. I wrote a small example using the Core Service to search for items in the content manager.
Console.WriteLine("FullTextQuery:");
var fullTextQuery = Console.ReadLine();
if (String.IsNullOrWhiteSpace(fullTextQuery) || fullTextQuery.Equals(":q", StringComparison.OrdinalIgnoreCase))
{
break;
}
Console.WriteLine("SearchIn IdRef:");
var searchInIdRef = Console.ReadLine();
var queryData = new SearchQueryData
{
FullTextQuery = fullTextQuery,
SearchIn = new LinkToIdentifiableObjectData
{
IdRef = searchInIdRef
}
};
var results = coreServiceClient.GetSearchResults(queryData);
results.ToList().ForEach(result => Console.WriteLine("{0} ({1})", result.Title, result.Id));
Add a reference to Tridion.ContentManager.CoreService.Client to your Visual Studio Project.
Code of the Core Service Client Provider:
public interface ICoreServiceProvider
{
CoreServiceClient GetCoreServiceClient();
}
public class CoreServiceDefaultProvider : ICoreServiceProvider
{
private CoreServiceClient _client;
public CoreServiceClient GetCoreServiceClient()
{
return _client ?? (_client = new CoreServiceClient());
}
}
And the client itself:
public class CoreServiceClient : IDisposable
{
public SessionAwareCoreServiceClient ProxyClient;
private const string DefaultEndpointName = "netTcp_2011";
public CoreServiceClient(string endPointName)
{
if(string.IsNullOrWhiteSpace(endPointName))
{
throw new ArgumentNullException("endPointName", "EndPointName is not specified.");
}
ProxyClient = new SessionAwareCoreServiceClient(endPointName);
}
public CoreServiceClient() : this(DefaultEndpointName) { }
public string GetApiVersionNumber()
{
return ProxyClient.GetApiVersion();
}
public IdentifiableObjectData[] GetSearchResults(SearchQueryData filter)
{
return ProxyClient.GetSearchResults(filter);
}
public IdentifiableObjectData Read(string id)
{
return ProxyClient.Read(id, new ReadOptions());
}
public ApplicationData ReadApplicationData(string subjectId, string applicationId)
{
return ProxyClient.ReadApplicationData(subjectId, applicationId);
}
public void Dispose()
{
if (ProxyClient.State == CommunicationState.Faulted)
{
ProxyClient.Abort();
}
else
{
ProxyClient.Close();
}
}
}
When you want to perform CRUD actions through the core service you can implement the following methods in the client:
public IdentifiableObjectData CreateItem(IdentifiableObjectData data)
{
data = ProxyClient.Create(data, new ReadOptions());
return data;
}
public IdentifiableObjectData UpdateItem(IdentifiableObjectData data)
{
data = ProxyClient.Update(data, new ReadOptions());
return data;
}
public IdentifiableObjectData ReadItem(string id)
{
return ProxyClient.Read(id, new ReadOptions());
}
To construct a data object of e.g. a Component you can implement a Component Builder class that implements a create method that does this for you:
public ComponentData Create(string folderUri, string title, string content)
{
var data = new ComponentData()
{
Id = "tcm:0-0-0",
Title = title,
Content = content,
LocationInfo = new LocationInfo()
};
data.LocationInfo.OrganizationalItem = new LinkToOrganizationalItemData
{
IdRef = folderUri
};
using (CoreServiceClient client = provider.GetCoreServiceClient())
{
data = (ComponentData)client.CreateItem(data);
}
return data;
}
Hope this gets you started.
Can I create a Controller that simply returns an image asset?
I would like to route this logic through a controller, whenever a URL such as the following is requested:
www.mywebsite.com/resource/image/topbanner
The controller will look up topbanner.png and send that image directly back to the client.
I've seen examples of this where you have to create a View - I don't want to use a View. I want to do it all with just the Controller.
Is this possible?
Use the base controllers File method.
public ActionResult Image(string id)
{
var dir = Server.MapPath("/Images");
var path = Path.Combine(dir, id + ".jpg"); //validate the path for security or use other means to generate the path.
return base.File(path, "image/jpeg");
}
As a note, this seems to be fairly efficient. I did a test where I requested the image through the controller (http://localhost/MyController/Image/MyImage) and through the direct URL (http://localhost/Images/MyImage.jpg) and the results were:
MVC: 7.6 milliseconds per photo
Direct: 6.7 milliseconds per photo
Note: this is the average time of a request. The average was calculated by making thousands of requests on the local machine, so the totals should not include network latency or bandwidth issues.
Using the release version of MVC, here is what I do:
[AcceptVerbs(HttpVerbs.Get)]
[OutputCache(CacheProfile = "CustomerImages")]
public FileResult Show(int customerId, string imageName)
{
var path = string.Concat(ConfigData.ImagesDirectory, customerId, "\\", imageName);
return new FileStreamResult(new FileStream(path, FileMode.Open), "image/jpeg");
}
I obviously have some application specific stuff in here regarding the path construction, but the returning of the FileStreamResult is nice and simple.
I did some performance testing in regards to this action against your everyday call to the image (bypassing the controller) and the difference between the averages was only about 3 milliseconds (controller avg was 68ms, non-controller was 65ms).
I had tried some of the other methods mentioned in answers here and the performance hit was much more dramatic... several of the solutions responses were as much as 6x the non-controller (other controllers avg 340ms, non-controller 65ms).
To expland on Dyland's response slightly:
Three classes implement the FileResult class:
System.Web.Mvc.FileResult
System.Web.Mvc.FileContentResult
System.Web.Mvc.FilePathResult
System.Web.Mvc.FileStreamResult
They're all fairly self explanatory:
For file path downloads where the file exists on disk, use FilePathResult - this is the easiest way and avoids you having to use Streams.
For byte[] arrays (akin to Response.BinaryWrite), use FileContentResult.
For byte[] arrays where you want the file to download (content-disposition: attachment), use FileStreamResult in a similar way to below, but with a MemoryStream and using GetBuffer().
For Streams use FileStreamResult. It's called a FileStreamResult but it takes a Stream so I'd guess it works with a MemoryStream.
Below is an example of using the content-disposition technique (not tested):
[AcceptVerbs(HttpVerbs.Post)]
public ActionResult GetFile()
{
// No need to dispose the stream, MVC does it for you
string path = Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "App_Data", "myimage.png");
FileStream stream = new FileStream(path, FileMode.Open);
FileStreamResult result = new FileStreamResult(stream, "image/png");
result.FileDownloadName = "image.png";
return result;
}
This might be helpful if you'd like to modify the image before returning it:
public ActionResult GetModifiedImage()
{
Image image = Image.FromFile(Path.Combine(Server.MapPath("/Content/images"), "image.png"));
using (Graphics g = Graphics.FromImage(image))
{
// do something with the Graphics (eg. write "Hello World!")
string text = "Hello World!";
// Create font and brush.
Font drawFont = new Font("Arial", 10);
SolidBrush drawBrush = new SolidBrush(Color.Black);
// Create point for upper-left corner of drawing.
PointF stringPoint = new PointF(0, 0);
g.DrawString(text, drawFont, drawBrush, stringPoint);
}
MemoryStream ms = new MemoryStream();
image.Save(ms, System.Drawing.Imaging.ImageFormat.Png);
return File(ms.ToArray(), "image/png");
}
You can create your own extension and do this way.
public static class ImageResultHelper
{
public static string Image<T>(this HtmlHelper helper, Expression<Action<T>> action, int width, int height)
where T : Controller
{
return ImageResultHelper.Image<T>(helper, action, width, height, "");
}
public static string Image<T>(this HtmlHelper helper, Expression<Action<T>> action, int width, int height, string alt)
where T : Controller
{
var expression = action.Body as MethodCallExpression;
string actionMethodName = string.Empty;
if (expression != null)
{
actionMethodName = expression.Method.Name;
}
string url = new UrlHelper(helper.ViewContext.RequestContext, helper.RouteCollection).Action(actionMethodName, typeof(T).Name.Remove(typeof(T).Name.IndexOf("Controller"))).ToString();
//string url = LinkBuilder.BuildUrlFromExpression<T>(helper.ViewContext.RequestContext, helper.RouteCollection, action);
return string.Format("<img src=\"{0}\" width=\"{1}\" height=\"{2}\" alt=\"{3}\" />", url, width, height, alt);
}
}
public class ImageResult : ActionResult
{
public ImageResult() { }
public Image Image { get; set; }
public ImageFormat ImageFormat { get; set; }
public override void ExecuteResult(ControllerContext context)
{
// verify properties
if (Image == null)
{
throw new ArgumentNullException("Image");
}
if (ImageFormat == null)
{
throw new ArgumentNullException("ImageFormat");
}
// output
context.HttpContext.Response.Clear();
context.HttpContext.Response.ContentType = GetMimeType(ImageFormat);
Image.Save(context.HttpContext.Response.OutputStream, ImageFormat);
}
private static string GetMimeType(ImageFormat imageFormat)
{
ImageCodecInfo[] codecs = ImageCodecInfo.GetImageEncoders();
return codecs.First(codec => codec.FormatID == imageFormat.Guid).MimeType;
}
}
public ActionResult Index()
{
return new ImageResult { Image = image, ImageFormat = ImageFormat.Jpeg };
}
<%=Html.Image<CapchaController>(c => c.Index(), 120, 30, "Current time")%>
Why not go simple and use the tilde ~ operator?
public FileResult TopBanner() {
return File("~/Content/images/topbanner.png", "image/png");
}
You can write directly to the response but then it isn't testable. It is preferred to return an ActionResult that has deferred execution. Here is my resusable StreamResult:
public class StreamResult : ViewResult
{
public Stream Stream { get; set; }
public string ContentType { get; set; }
public string ETag { get; set; }
public override void ExecuteResult(ControllerContext context)
{
context.HttpContext.Response.ContentType = ContentType;
if (ETag != null) context.HttpContext.Response.AddHeader("ETag", ETag);
const int size = 4096;
byte[] bytes = new byte[size];
int numBytes;
while ((numBytes = Stream.Read(bytes, 0, size)) > 0)
context.HttpContext.Response.OutputStream.Write(bytes, 0, numBytes);
}
}
Below code utilizes System.Drawing.Bitmap to load the image.
using System.Drawing;
using System.Drawing.Imaging;
public IActionResult Get()
{
string filename = "Image/test.jpg";
var bitmap = new Bitmap(filename);
var ms = new System.IO.MemoryStream();
bitmap.Save(ms, ImageFormat.Jpeg);
ms.Position = 0;
return new FileStreamResult(ms, "image/jpeg");
}
UPDATE: There are better options than my original answer. This works outside of MVC quite well but it's better to stick with the built-in methods of returning image content. See up-voted answers.
You certainly can. Try out these steps:
Load the image from disk in to a byte array
cache the image in the case you expect more requests for the image and don't want the disk I/O (my sample doesn't cache it below)
Change the mime type via the Response.ContentType
Response.BinaryWrite out the image byte array
Here's some sample code:
string pathToFile = #"C:\Documents and Settings\some_path.jpg";
byte[] imageData = File.ReadAllBytes(pathToFile);
Response.ContentType = "image/jpg";
Response.BinaryWrite(imageData);
Hope that helps!
Solution 1: To render an image in a view from an image URL
You can create your own extension method:
public static MvcHtmlString Image(this HtmlHelper helper,string imageUrl)
{
string tag = "<img src='{0}'/>";
tag = string.Format(tag,imageUrl);
return MvcHtmlString.Create(tag);
}
Then use it like:
#Html.Image(#Model.ImagePath);
Solution 2: To render image from database
Create a controller method that returns image data like below
public sealed class ImageController : Controller
{
public ActionResult View(string id)
{
var image = _images.LoadImage(id); //Pull image from the database.
if (image == null)
return HttpNotFound();
return File(image.Data, image.Mime);
}
}
And use it in a view like:
# { Html.RenderAction("View","Image",new {id=#Model.ImageId})}
To use an image rendered from this actionresult in any HTML, use
<img src="http://something.com/image/view?id={imageid}>
This worked for me.
Since I'm storing images on a SQL Server database.
[HttpGet("/image/{uuid}")]
public IActionResult GetImageFile(string uuid) {
ActionResult actionResult = new NotFoundResult();
var fileImage = _db.ImageFiles.Find(uuid);
if (fileImage != null) {
actionResult = new FileContentResult(fileImage.Data,
fileImage.ContentType);
}
return actionResult;
}
In the snippet above _db.ImageFiles.Find(uuid) is searching for the image file record in the db (EF context). It returns a FileImage object which is just a custom class I made for the model and then uses it as FileContentResult.
public class FileImage {
public string Uuid { get; set; }
public byte[] Data { get; set; }
public string ContentType { get; set; }
}
you can use File to return a file like View, Content etc
public ActionResult PrintDocInfo(string Attachment)
{
string test = Attachment;
if (test != string.Empty || test != "" || test != null)
{
string filename = Attachment.Split('\\').Last();
string filepath = Attachment;
byte[] filedata = System.IO.File.ReadAllBytes(Attachment);
string contentType = MimeMapping.GetMimeMapping(Attachment);
System.Net.Mime.ContentDisposition cd = new System.Net.Mime.ContentDisposition
{
FileName = filename,
Inline = true,
};
Response.AppendHeader("Content-Disposition", cd.ToString());
return File(filedata, contentType);
}
else { return Content("<h3> Patient Clinical Document Not Uploaded</h3>"); }
}
Look at ContentResult. This returns a string, but can be used to make your own BinaryResult-like class.
if (!System.IO.File.Exists(filePath))
return SomeHelper.EmptyImageResult(); // preventing JSON GET/POST exception
else
return new FilePathResult(filePath, contentType);
SomeHelper.EmptyImageResult() should return FileResult with existing image (1x1 transparent, for example).
This is easiest way if you have files stored on local drive.
If files are byte[] or stream - then use FileContentResult or FileStreamResult as Dylan suggested.
I see two options:
1) Implement your own IViewEngine and set the ViewEngine property of the Controller you are using to your ImageViewEngine in your desired "image" method.
2) Use a view :-). Just change the content type etc.
You could use the HttpContext.Response and directly write the content to it (WriteFile() might work for you) and then return ContentResult from your action instead of ActionResult.
Disclaimer: I have not tried this, it's based on looking at the available APIs. :-)
I also encountered similar requirement,
So in my case I make a request to Controller with the image folder path, which in return sends back a ImageResult object.
Following code snippet illustrate the work:
var src = string.Format("/GenericGrid.mvc/DocumentPreviewImageLink?fullpath={0}&routingId={1}&siteCode={2}", fullFilePath, metaInfo.RoutingId, da.SiteCode);
if (enlarged)
result = "<a class='thumbnail' href='#thumb'>" +
"<img src='" + src + "' height='66px' border='0' />" +
"<span><img src='" + src + "' /></span>" +
"</a>";
else
result = "<span><img src='" + src + "' height='150px' border='0' /></span>";
And in the Controller from the the image path I produce the image and return it back to the caller
try
{
var file = new FileInfo(fullpath);
if (!file.Exists)
return string.Empty;
var image = new WebImage(fullpath);
return new ImageResult(new MemoryStream(image.GetBytes()), "image/jpg");
}
catch(Exception ex)
{
return "File Error : "+ex.ToString();
}
Read the image, convert it to byte[], then return a File() with a content type.
public ActionResult ImageResult(Image image, ImageFormat format, string contentType) {
using (var stream = new MemoryStream())
{
image.Save(stream, format);
return File(stream.ToArray(), contentType);
}
}
}
Here are the usings:
using System.Drawing;
using System.Drawing.Imaging;
using System.IO;
using Microsoft.AspNetCore.Mvc;
Yes you can return Image
public ActionResult GetImage(string imageFileName)
{
var path = Path.Combine(Server.MapPath("/Images"), imageFileName + ".jpg");
return base.File(path, "image/jpeg");
}
(Please don't forget to mark this as answer)
From a byte[] under Core 3.2, you can use:
public ActionResult Img(int? id) {
MemoryStream ms = new MemoryStream(GetBytes(id));
return new FileStreamResult(ms, "image/png");
}